php - subtract 6 hours from date('g:i a', strtotime($time_date_data));

Question

I am using the following code to transform a universal time code into something a little more user friendly.

$meeting_time = date('g:i a', strtotime($time_date_data));

But now I need to subtract 6 hours from meeting_time. Should I do it after the code above or can I work it into the same date function?

Something like:

$meeting_time = date('g:i a' - 6, strtotime($time_date_data));

Answer 1

$meeting_time = date('g:i a', strtotime($time_date_data) - 60 * 60 * 6);

String-to-time (strtotime) returns a Unix Time Stamp which is in seconds (since Epoch), so you can simply subtract the 21600 seconds, before converting it back to the specified date format.